Microsoft looked at how people actually spend a workday inside its own tools and found the average person gets interrupted every two minutes: 275 pings, meetings, and messages during core hours, plus 117 emails and 153 chat messages landing on top of that. Read that number again. Not 275 tasks. 275 interruptions. If you manage a team, your day is worse than the average, because a large share of those interruptions are aimed specifically at you.
Most managers respond to this by trying to find more time. Earlier mornings, protected lunches, a Sunday-night planning ritual. None of it holds, and the reason it doesn’t hold is that time was never the constraint. The constraint is how much it costs you to move your attention from one thing to another. That cost has a name in the research, and once you see it, you stop trying to manage your calendar and start managing your switches.
The tax nobody puts on the invoice
The American Psychological Association has been clear about this for two decades: the mental work of shifting between tasks can eat up to 40% of your productive time. Each individual switch is cheap, a few tenths of a second while your brain does what the researchers call goal shifting (“I want to do this now instead of that”) and rule activation (“turn off the rules for that, turn on the rules for this”). The problem is volume. When you switch a few hundred times a day, those tenths of a second compound into hours, and the errors compound with them.
Gloria Mark’s team at UC Irvine put a harder number on the recovery side. After an interruption, it takes an average of 23 minutes and 15 seconds to return to the original task, and people rarely go straight back; her data shows an average of two intervening tasks before you land where you started. Her more recent work found the average time we spend on a single screen before switching has collapsed from about two and a half minutes in 2004 to roughly 47 seconds today. We are not getting interrupted. We are interrupting ourselves, constantly, and calling it work.
That 40% figure is not a productivity-blog exaggeration. It is the difference between a manager who leaves at 5:30 with the important thing done and one who is still answering messages at 10 p.m. because the important thing never got a clean run at their attention.
Why your brain can’t just flip a switch
Here is the piece most time-management advice misses. When you leave a task unfinished to handle something else, part of your attention stays behind. Sophie Leroy, a researcher at the University of Washington Bothell, named this in a 2009 study with a title every manager should feel in their bones: “Why is it so hard to do my work?” She called the effect attention residue, and she defined it as the state where part of your attention is still stuck on the previous task instead of fully on the one in front of you.
Her experiments showed something specific and useful: the strongest predictor of how much residue you carry is not how hard the previous task was. It is whether you left it unfinished. A task brought to a clean stopping point generates far less residue than one you abandoned mid-thought. People who switched away from an incomplete task performed measurably worse on the next task, and the more residue they carried, the worse they did.
Sit with what that means for a manager’s day. You are almost never at a clean stopping point. You are drafting the budget when someone drops by with a client problem. You are three sentences into a performance note when a Slack channel lights up. Every one of those switches leaves you partly on the last thing, which is exactly why you can spend eight hours fully busy and produce nothing you would call finished. You weren’t lazy. You were carrying residue all day.
Managers are switching machines by design
Individual contributors can, on a good day, defend a block of hours. A manager’s job is structurally the opposite. The role is a series of context switches: a one-on-one, then a vendor call, then a hallway question about vacation, then a strategy doc, then a fire. Microsoft’s data found that 57% of meetings now happen as ad hoc calls with no calendar invite at all, and that half of all meetings land squarely in the two windows when focus is highest, 9 to 11 in the morning and 1 to 3 in the afternoon. The interruptions are not an interruption of the job. For managers, they increasingly are the job.
I learned this the expensive way during a fractional COO engagement a few years back. The company had asked me to rebuild their operations reporting, real analytical work that needed uninterrupted stretches. I was also the person everyone escalated to. For the first three weeks I did what most managers do: I kept my messages open so I could be responsive, and I chipped at the reporting project between fires. At the end of those three weeks the reporting was maybe 20% done, and I was exhausted in the particular way that has nothing to do with hours worked. I was exhausted from switching.
What fixed it was not more discipline. It was accepting that responsiveness and depth cannot share the same hour, and structuring the day so they didn’t have to. Two ninety-minute blocks a day with messages closed and my calendar marked. Everything reactive got batched into the space between. The reporting was done in nine working days. The team did not fall apart in my absence, which is the fear that keeps most managers permanently available. This is the same trap I’ve written about in why so many managers become their team’s bottleneck: the belief that being reachable at every moment is the job, when it’s often the thing keeping the real job from getting done.
The one-minute habit that cuts the residue
You cannot eliminate switching. You manage a team; interruptions are the terrain. What you can do is change how you switch, and the research points at a specific intervention.
In a 2018 follow-up published in Organization Science, Leroy and Theresa Glomb tested something they called a ready-to-resume plan. When you get interrupted, before you turn to the new thing, you take under a minute to note where you were: where to pick up, what you had planned to do next, what’s still open. That’s it. Across four studies, people who wrote that quick plan carried less attention residue and performed better on the interrupting task. The brain, given a clear marker of where it left off, stops guarding the unfinished task and frees up to focus on the new one.
This is deceptively small and genuinely powerful. The reason an interruption costs 23 minutes is that your brain doesn’t trust it can find its way back, so it keeps a thread running in the background the whole time. A ready-to-resume note is you telling your brain, in writing, “I’ve got the return handled, you can let go.” Leroy’s own summary of the mechanism is blunt: it is not cognitively possible to fully focus on two tasks at once while one stays incomplete. The note is how you complete the loop even when you can’t complete the task.
Three things that actually move the needle, in order of leverage:
Batch the reactive stuff instead of sprinkling it. Two or three defined windows a day for messages and quick asks beats an always-open channel. You are trading responsiveness measured in seconds for responsiveness measured in a few hours, and almost nothing on a manager’s plate genuinely needs the seconds. Deciding what deserves a slot at all is its own skill, which is really a question of what work you let onto your plate in the first place.
Leave a breadcrumb before every forced switch. When someone pulls you off something, spend the fifteen seconds to jot where you were before you engage. It feels like it slows you down. It does the opposite.
Protect two real blocks, not the whole day. You are not going to get uninterrupted mornings; stop chasing them. Two ninety-minute blocks with notifications off is realistic and covers most of the deep work a manager owes the week. This is the practical core of defending focus time when everyone needs something from you.
None of this requires an app or a system. It requires treating your attention as the scarce resource it is, rather than your hours. The manager who understands why the brain runs out of capacity long before the day does is already halfway there.
You’re also the interruption
One more thing, and it’s the one managers least want to hear. You are not only the victim of the switching tax. You are a major source of it for your team.
Every “quick question,” every drive-by Slack, every 4:45 “can you jump on a call,” you are imposing the same 23-minute cost on someone else that you resent when it lands on you. Microsoft found that 48% of employees and 52% of leaders already describe their work as chaotic and fragmented. A meaningful slice of that fragmentation, on any given team, traces back to a manager who fires off thoughts the moment they occur because sending it clears it off their own plate.
The fix is to batch your outbound interruptions the same way you batch your inbound ones. Hold the six small things and deliver them in one one-on-one or one message, rather than six separate detonations across someone’s afternoon. Ask yourself before you hit send: does this need an answer in the next ten minutes, or am I just offloading it? Most of the time you are offloading, and the cost of that habit shows up in your team’s output long before anyone complains about it. It’s a close cousin to the meeting audit most calendars badly need: the interruptions you create are as worth auditing as the ones on your schedule.
The managers who protect their own attention and their team’s attention are not the ones with the best productivity system. They’re the ones who stopped believing the problem was a shortage of hours. It never was. It was the tax you pay every time you move your mind from one thing to another, several hundred times a day, without ever noticing the bill.